      * {
            margin: 0;
            padding: 0;
        }
        
/*        body {
            max-width: 1920px;
        } */
        
        #btn {
            position: absolute;
            top: 22%;
            left: 298px;
            height: 75px;
            border: 0;
            border-left: 1px solid rgb(23, 32, 43, 0.2);
            background: #AA3344;
            color: #fff;
            cursor: pointer;
        }
        
        .box {
            float: left;
            position: relative;
            left: 0;
            height: 90%;
            width: 20%;
            margin-left: 0;
            display: block;
            background-color: #a34;
            -moz-transition: margin-left 1s;
            transition: margin-left 1s;
        }
        
/*        aside ul li {
            height: 40px;
            line-height: 40px;
            border-top: 1px solid #fff;
            border-bottom: 1px solid #fff;
            list-style-type: none;
            text-align: center;
        }
        
        aside ul li a {
            width: 100%;
            height: 100%;
            text-decoration-line: none;
            color: #fff;
            display: block;
        }
        
        aside ul li a:hover {
            background: #d3d;
        } */
        
        section {
            width: 100%;
            height: 100%;
            background: #d4d4d4;
            /* height: 1000px; */
        }
        
        section h1 {
            text-align: center;
            border-bottom: 1px solid #fff;
        }